fix(web): remove obsolete dev dependency override

[dgdavid]

The override was introduced in commit 2d695e8, but is no longer required since upgrading to Jest > 30.

It previously forced the installation of @tootallnate/once v2.0, which has known vulnerabilities in versions prior to 3.0.1.

Fixes bsc#1259117 (protected link).

Before

❯ npm ls @tootallnate/once
agama@ /home/dgdavid/development/suse/agama/web
└─┬ jest-environment-jsdom@30.2.0
  └─┬ jsdom@22.1.0 overridden
    └─┬ http-proxy-agent@5.0.0
      └── @tootallnate/once@2.0.0

After

❯ npm ls @tootallnate/once                   
agama@ /home/dgdavid/development/suse/agama/web
└── (empty)